Acer japonicum (Downy Japanese Maple or Fullmoon Maple; Japanese: ハウチワカエデ hauchiwakaede) is a species of maple native to Japan, on Honshū, Hokkaidō, Kyūshū (Nagasaki Prefecture), and in addition southern Korea.
It’s a small deciduous tree rising to five–10 m (hardly ever 15 m) tall, with a trunk as much as 40 cm diameter. The bark is clean on younger bushes, turning into tough and scaly on previous bushes. The shoots are slender, and thinly downy with whitish hairs. The leaves are rounded, 7–15 cm diameter with 9–13 (hardly ever 7) serrate lobes incised to half or much less of the diameter of the leaf; they’re downy at first with white hairs, the hairs principally misplaced by late summer time besides on the veins and the underside of the leaf; the petiole is 2–4 cm lengthy and furry. In autumn, the leaves flip shiny orange to darkish crimson. The flowers are 1 cm diameter, darkish purplish-red with 5 sepals and petals; they’re produced 10–15 collectively in drooping corymbs in early spring because the leaves begin to open. The fruit is a paired samara with the nutlets 7 mm diameter with a 20–25 mm wing, hanging beneath the leaves.
The intently associated species Acer shirasawanum (Japanese, オオイタヤメイゲツ ooitayameigetsu) from southern Japan is typically included as a subspecies of A. japonicum. It’s distinct in its hairless shoots, and normally smaller leaves. One other associated species, Acer sieboldianum (Japanese: コハウチワカエデ kohauchiwakaede), is finest distinguished by its yellow (not crimson) flowers, and clean bark even on previous bushes. It’s extra simply distinguished from Acer palmatum, as that species hardly ever has leaves with greater than seven lobes.
A. japonicum is regularly cultivated as a decorative plant in temperate areas of Europe, North America, and elsewhere, although a lot much less generally than A. palmatum. In cultivation, it’s typically solely a shrubby tree with a number of trunks becoming a member of at ground-level.
Its most well-liked rising circumstances are just like these of A. palmatum, however it’s generally thought of extra tolerant of chilly, particularly in comparison with the extra delicate cultivars of the latter.
Quite a few cultivars have been chosen, a few of which have their very own widespread names (e.g. “Grape-leaf maple” for A. japonicum ‘Vitifolium’). Different in style cultivars are ‘Aconitifolium’ which has deeply incised leaves, and ‘Inexperienced Cascade’, with drooping to pendulous branches. Due to their variation from the wild species, some cultivars are troublesome to assign to species, and so they have typically been mis-labeled as cultivars of the opposite associated species; notably ‘Aureum’ has generally been cited as a cultivar of A. japonicum, however is definitely derived from A. shirasawanum.
Cultivars of this maple are present in virtually each maple assortment together with Esveld Aceretum (Boskoop, Netherlands) and the massive Acer part of Arnold Arboretum (Boston, Massachusetts). They’re additionally widespread in additional basic collections of horticulture.